Preparation method of SiC whiskers

Abstract

The invention relates to the field of SiC whiskers, particularly a preparation method of SiC crystal whiskers, which is characterized by comprising the following steps: by using Elkem silicon micropowder as a silicon source, graphite as a carbon source and Na3AlF6 as a catalyst, adding SiO2 micropowder and Na3AlF6 into a graphite crucible in a C / Si mol ratio of (7.5-8):1 and Si / Al mol ratio of (4-6):1, wherein the inner wall of the graphite crucible is the substrate for growing the SiC whiskers; charging argon into a hot pressing furnace as a protective gas for growing the SiC whiskers; and putting in a vacuum carbon tube furnace, charging argon, and keeping the temperature at 1300-1500 DEG C for 1-3 hours. Compared with the prior art, the invention has the advantages of wide raw material sources, low cost, no environmental pollution, long length-to-diameter ratio of prepared whiskers (up to 60-200), smooth whisker surface and simple preparation technique, and can control the growth of the whiskers by controlling the temperature and atmosphere in the production process.

Description

technical field [0001] The invention relates to the field of SiC whiskers, in particular to a preparation method of SiC whiskers. Background technique [0002] SiC whiskers are highly oriented short fiber single crystals used as reinforcement and toughening materials for composite materials. The preparation method of SiC whiskers generally adopts the method of carbothermal reduction, that is, the silicon source, the carbon source and the catalyst are mixed in a certain proportion, reacted under high temperature conditions in a non-oxidizing atmosphere, and the synthetic product is removed by carbon removal and pickling. Impurities. Since Professor Cutler of the University of Utah in the mid-1970s invented rice husks to produce SiC whiskers, SiC whiskers made from rice husks have been greatly developed, and the content of SiC whiskers in the produced SiC has only accounted for 10 % increased to 20~25%. Tokai Carbon Company of Japan and Ross Alamos Company of the United Sta...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a method for preparing SiC whiskers, using a new catalyst to solve the problems of high cost and complicated preparation process in the production of SiC whiskers, reduce production costs, and improve production efficiency and product quality